Heartsong (or Howl)
by Kalira69
Summary: Of all the things Tenzou may have expected accompanying Kakashi-senpai to the onsen today, to finally - finally! - feel the tug of his soulmate being recognised was not one of them. Now if only he had any idea what to do with the revelation he's just been gifted. . .


Written for Day 1 of KakaYama Week - prompt: soulmates.

I love soulmate AUs, so naturally when I found out about this event (a month ago, amid a slew of deadlines) and knew I could probably only pull off _some_ of the prompts for the week, I knew Day 1 would definitely be one of them.

This is a new flavour of soulmate AU for me, though I've done one or two other singing-related ones before.

* * *

Tenzou pulled up short just inside the doorway, ducked his head in a polite bow, and stepped out of the way, allowing a distracted trio of ninja to bypass him on their way into the bathhouse. When they had, he realised that he had lost Kakashi. Of course.

"Senpai?" Tenzou said, keeping his voice courteously low, as he walked further out towards the soaking pools.

A familiar hand rose into view on the far side of a rock planter with ferns spilling out of it, and Tenzou sighed, relieved, making his way towards Kakashi, apparently already lounging in the onsen. He tilted his head back and smiled at Tenzou when he rounded the plants, eye closing cheerfully.

Tenzou smiled back anyway, sliding his towel off and stepping down into the water.

Something warm and pulsing _curled_ in his chest, winding around his heart and lighting in his blood, and Tenzou gasped, slipping. The sensation of squeezing warmth went away even as he splashed down into the hot water almost too quickly to stand the temperature shift, and Kakashi caught him before he could fall in so far as to be completely underwater.

Tenzou flushed, cringing.

"Careful, Tenzou." Kakashi said lightly, half lifting Tenzou and nudging him into a seat against the wall before sinking back into his own, stretching his arms out along the smooth rock edge of the pool.

"Thank you, senpai." Tenzou said quietly, and rubbed his chest with one hand, just over his still-fluttering heart. He quietly looked around as he settled into his seat, trying to see who was nearby and could have sparked the sensation of a nascent bond in him.

Tenzou had never felt it before, but there was no way he could have mistaken it, for all the times he had doubted it could truly be so simple - he had felt _his soulmate_. They must have been so quiet from where he stood that he could barely hear at all, because he hadn't consciously realised anyone was singing, but he had _heard it_, and his heart had responded, and-

And then had stopped, when he fell, probably because he had distracted _everyone_, and now Tenzou had finally gotten a hint of his soulmate's _existence_ at least and he had _no idea_ who it was! He whined softly and sank lower in the water, sighing.

Kakashi hummed, patting his shoulder absently, and lounged a little deeper in the water.

Tenzou smiled faintly, still surreptitiously examining the other guests of the onsen through half-closed eyes, needing to know but not wishing to be noticeable. Beside him, Kakashi hummed, then . . . began to sing, to Tenzou's surprise.

And Tenzou's eyes widened, a shudder running through him, as the curling warm _pull_ towards his soulmate returned. _Kakashi_. Tenzou swallowed and turned shakily to look at Kakashi, who was slouched lazily low in the water, his one visible eye heavy-lidded. His voice was soft but unmistakable, and Tenzou could barely focus enough to catch the words - it was familiar, though Tenzou didn't know it well himself; a ballad that was half love story and half cautionary tale, filled with tricks and misdirections. It didn't truly matter, because Kakashi's voice was calling to his giddy, warm heart, regardless of the words.

He tried not to clutch at his chest, feeling his cheeks flush red, warmth flooding them.

_Kakashi-senpai_.

Tenzou had- had finally found his soulmate.

He had never considered that Kakashi- Not in _years_, anyway- And. . . He would never have thought seriously; if nothing else, _surely_ he would have thought he'd heard Kakashi sing, at some point, over the years they had known each other, all the time they had spent together.

But of course, it seemed, he had not after all. Somehow. Kakashi never had. Not when he was near enough. . .

Tenzou was breathless and his heart, in the tight clasp of that curling warmth, was fluttering and beating probably too fast. Particularly for being in the heat of the onsen. He should- He should probably get out.

He sank a little lower and wished faintly they were in an uncultivated onsen or- or the river or _anywhere_ he could have hidden himself completely beneath the water without being rude. He didn't _want_ to leave, certainly not while this feeling lingered, while Kakashi - while _his soulmate_ \- was still singing.

"Ah, look, the dog who thinks he can sing!" a ninja Tenzou didn't recognise said, pausing near them. "We have to put up with this again, Hatake?" he asked, grinning. "Why you always got to start this singing in the bath nonsense? Just relax quietly. You know, like a civilised hound."

Kakashi cocked his head without stopping his song. He dragged one syllable out and dropped it into a hum, then caught a deep breath and tipped his head back. Tenzou startled, then sank down a little further in the water, eyes wide, as he _bayed_ like an actual hunting dog on a scent, his voice piercing and far too loud even _before_ it bounced in ringing echoes off the water and the rocks surrounding the pool.

"Oof." the man put a hand to his chest and faked a stagger.

Tenzou's heart fluttered and throbbed, still firmly in the grasp of his soulmate's voice, though this was hardly a _song_. Apparently. . . Apparently it counted, for a soulmate bond, however, for Tenzou's was twining around his heart tight and warm.

The baying finally trailed away only after a very, _very_ long note. Kakashi laughed, rolling his shoulders, and turned his head to wink playfully at Tenzou before looking up again. "This dog _knows_ he can sing, Jirou." he said lightly, and the other man snorted and shook his head, smiling faintly, and walked on without further comment.

Tenzou found a smile of his own somewhere and shook his head slightly as Kakashi looked at him. It must have looked passably normal, because Kakashi only grinned back and stretched languidly, humming softly as he settled once more. Tenzou shivered as the nascent bond flared back to life, half wrecked by it but unable to resent the feeling in the slightest.

He had, fortunately, just about managed to calm himself back down to an even keel by the time they were leaving. He had also. . .

Zipping up his flak vest over his clean shirt, Tenzou bowed his head and looked sideways at Kakashi, his heart fluttering and his throat tight. He was . . . sure, though. He couldn't have gotten much _more_ sure, with Kakashi's singing _right beside him_, and- And it was _Kakashi_.

Even if Tenzou _hadn't_ been . . . hoping, for his soulmate, as he had been - it was Kakashi- How could he be anything other than sure? Not only of what the bond was telling him but of how he _felt_ about it?

"Senpai?" Tenzou said softly, reaching out and pausing with his fingers just brushing Kakashi's sleeve at his elbow. Kakashi cocked his head and looked at Tenzou, smiling again, eye creasing and mouth shifting beneath his thin mask. "May I- Ehm."

Tenzou swallowed thickly as Kakashi watched him with a curious, half-concerned look.

His heart was in his throat as he opened his mouth and sang; despite his hopes for his soulmate over the years, Tenzou . . . didn't really sing. He never had been one of the people to _try_, not like that, so _boldly_, and it felt awkward to do so now. He had searched his mind for a song and he only remembered half a verse into a folk tale put to music that had stuck fast in his mind some months ago that it was about a mischievous cat who chased a dog. He blushed harder, but he didn't stop, voice wavering.

Kakashi touched his cheek, and Tenzou fell silent. It took him several long moments, his breathing unsteady and thin, to bring himself to look up to Kakashi's face rather than his chest just below his collarbones, which couldn't offer any judgement. Or- Or refusal.

Kakashi's eye betrayed perhaps a bit of surprise but he just . . . smiled at Tenzou, soft and fond, hand smoothing over Tenzou's shoulder. "Oh. Tenzou." he said softly, and sighed.

Tenzou swallowed, opening his mouth and stuttering awkwardly through several attempts at speech, flushing again. Kakashi brushed a fingertip over his mouth and he fell silent, eyes wide. Kakashi moved closer, bowing his head so near Tenzou's that their noses almost brushed.

Tenzou could hardly breathe, his heart fluttering in his chest even without the slightest hint of song from Kakashi this time. Kakashi met his gaze, but didn't move again.

"Kakashi-senpai?" Tenzou asked, voice low, a shiver running through him.

"What do you want, Tenzou?" Kakashi asked, fingertips trailing along his jaw. Tenzou licked his lips, then leaned across the tiny space yet between them and wound his arms around Kakashi, holding him close. Kakashi stiffened and shuddered, then quickly relaxed into him, bending in Tenzou's embrace, one hand settling at the nape of his neck as he breathed a soft _oh_ in Tenzou's ear.

"What am I allowed, senpai?" Tenzou asked, though he didn't release Kakashi. "I know what I want, I know what. . ." He flushed, ducking his chin. It bumped into Kakashi's shoulder, but he didn't flinch at the impact that jarred Tenzou's jaw, only stroked the back of Tenzou's neck lightly.

"I've . . . known." Kakashi said quietly, and Tenzou hummed curiously, then- His breath caught as he realised what Kakashi meant. "If," Kakashi pulled back just slightly, barely far enough to let their eyes meet once more, "you want me. . ."

"_Kakashi._" Tenzou's breath hitched again. "Kakashi, I-" he paused. "I want you." he said, barely able to get out the words, his cheeks warm and his fluttering heart feeling like it had lodged right at the base of his throat. "Please."

Kakashi all but sagged against him, going lax with a soft little sigh of relief, and Tenzou smiled, startled. Kakashi nuzzled his face, making a quiet crooning sound that pulled at the heat around his heart that said _soulmate_ all over again.

Tenzou nuzzled right into the touch himself, hugging Kakashi a little tighter, grin steadying and spreading across his face as he closed his eyes.

* * *

Kakashi has known Tenzou was his soulmate for quite a few years now - small Tenzou had a habit of humming to himself. Kakashi refused to put it on him before he had a chance to grow up and get to know himself and the world a little more, _without_ that pressure on him. (And Kakashi had to indulge his angst over it as well I'm sure.)


End file.
